Process for sequestering ammonia and the odor associated therewith

Abstract

Ammonia, particularly aqueous ammonia is sequestered in unexpected large amounts on zeolite molecular sieves having high proportions of silica with respect to alumina in their crystal frameworks. While conventional adsorption mechanisms are to some degree involved, it is apparent from the fact that the characteristic odor of ammonia is not detectable by the human sense of smell over the ammonia-loaded adsorbents indicates that other mechanisms are operable. These properties provide the basis for processes and products which are useful in removing ammonia from an environment to alleviate health hazards or unpleasant odor.

What is claimed is: 
     
       1. Process for sequestering ammonia and the odor associated therewith from the environment which comprises contacting and adsorbing at a temperature of from -25° C. to 100° C. the ammonia with a crystalline siliceous molecular sieve which has been at least partially activated, has the faujasite crystal structure, has pore diameters large enough to adsorb ammonia, has a capacity for adsorbed water not greater than 10 weight percent when measured at 25° C. and a water vapor pressure of 4.6 torr and has a framework SiO 2  /Al 2  O 3  ratio of at least 50, said contacting and adsorbing of said ammonia being to a sufficient degree that residual concentration thereof over the adsorbent are below the detection threshold of the human sense of smell. 
     
     
       2. Process according to claim 1 wherein the siliceous molecular sieve has a capacity for adsorbed water of not greater than 6 weight percent. 
     
     
       3. Process according to claim 1 wherein the siliceous molecular sieve is an aluminosilicate having a framework SiO 2  /Al 2  O 3  molar ratio of from 200 to 500. 
     
     
       4. Process according to claim 1 wherein the siliceous molecular sieve comprises a mixture of a silica polymorph and an aluminosilicate having a framework SiO 2  /Al 2  O 3  molar ratio of from 200 to 500. 
     
     
       5. Process according to claim 4 wherein the aluminosilicate is LZ-10. 
     
     
       6. Process for detecting the generation of ammonia by the action of bacteria on nitrogen-containing organic matter which comprises imparting to or maintaining in the environment of the nitrogen-containing organic matter in contact with the said bacteria a crystalline siliceous molecular sieve which has been at least partially activated, has pore diameters large enough to adsorb ammonia, has a capacity for adsorbed water not greater than 10 weight percent when measured at 25° C. and a water vapor pressure of 4.6 torr and has a framework SiO 2  /Al 2  O 3  ratio of at least 50, said molecular sieve containing in the adsorbed state a fragrance readily detected by the human sense of smell whereby any ammonia generated in said environment is adsorbed and displaces the said fragrance as an indication that ammonia is being generated.